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Background The impact that malnutrition at the time of starting antiretroviral therapy (ART) has on survival and the CD4 count response is not known. Methods A retrospective cohort study of patients attending the national HIV referral centre in Singapore who had a CD4 count less than 250 cells/μL and a measurement of body weight performed at the time of starting ART was carried out. Demographic and clinical variables were extracted from an existing database. Body mass index (BMI) was calculated from the weight in kilograms divided by the square of the height in metres. Moderate to severe malnutrition was defined as BMI less than 17 kg/m2. Intent-to-treat Cox models were used to determine the predictors of survival. Results A total of 394 patients were included in the analysis, of whom 79 died during a median study follow-up of 2.4 years. Moderate to severe malnutrition was present in 16% of patients at the time of starting ART, and was found to be a significant independent predictor of death [hazard ratio (HR) 2.19, 95% confidence interval (CI) 1.29–3.73, P=0.004 for those with BMI<17 compared with those with BMI>18.5] as were stage of disease (HR 2.47, 95% CI 1.20–5.07, P=0.014 for those who were at stage C compared with those at stage A) and the type of ART [HR 0.50, 95% CI 0.27–0.93, P=0.03 for highly active antiretroviral therapy (HAART) compared with non-HAART treatment]. Malnutrition did not impair the magnitude of the increase in CD4 count at 6 or 12 months. Conclusions Malnutrition at the time of starting ART was significantly associated with decreased survival, but the effect appeared not to be mediated by impaired immune reconstitution. Given the increasing access to ART in developing countries and the high frequency of HIV-associated wasting, studies of nutritional therapy as an adjunct to the initiation of HAART are urgently needed. [ABSTRACT FROM AUTHOR]

Microsatellites are now used ubiquitously as genetic markers. One important application is to the assessment of population subdivision and phylogenetic relatedness. Such applications require a method of estimation of genetic distance. Here we examine the most widely used measure of microsatellite genetic distance, Goldstein et al.'s delta-mu squared ([delta mu]2), with respect to a large data set of 213 markers typed across samples from four diverse human populations. We find that (delta mu)2 yields plausible interpopulation distances. For the first time, we report significant interpopulation differences in mean microsatellite length, although the effect of these differences on (delta mu)2 is negligible. However, we also show that the method is extremely sensitive to one or two loci that contribute extreme values, even when a sample size of >200 loci is used. Some of these extreme loci can be removed on the grounds that some alleles carry large indels, but for others there is no clear justification for exclusion a priori. Our data suggest a rather recent African/non-African split, with an upper limit of some 70,000-80,000 years ago.